Fire Stop and Method of Use Thereof

ABSTRACT

A fire stop dimensioned to fit a selected size opening. The fire stop comprises end plates, a central shaft member retaining the end plates apart from one another, and a core between the end plates that comprises fire putty and mineral wool. The thickness and density of the mineral wool layer and/or the fire putty layer are chosen to achieve a particular fire rating within the constraints of the overall dimensional thickness of the slab. The fire stop has a low profile rendering it non-obstructing, can be inserted by a single installer from above a floor slab or into a wall, and further can be removed for inspection and/or replacement as needed. The fire putty layer swells under heat filling remaining gaps between the fire stop and the opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

None

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None

PARTIES TO A JOINT RESEARCH AGREEMENT

None

REFERENCE TO A SEQUENCE LISTING

None

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates generally to devices utilized as fire stops, and more specifically to a unitary fire stop assembly for insertion into floor or wall openings.

2. Description of Related Art

During construction, particularly of commercial buildings, various openings are made in concrete slabs or similar surfaces. The openings are typically drilled through the slab and are dimensioned to accommodate installation of electrical conduits and/or boxes, and plumbing and similar apparatuses that must pass from one floor to another or through a wall.

Subsequently, when a building is remodeled, the aforementioned electrical, plumbing and similar apparatuses are removed, leaving a hole through the wall or floor slab. Unfortunately, if such holes are left unfilled, fire consuming portions of one floor can readily pass through the hole to another floor, thereby creating a dangerous possibility of a spreading fire. Accordingly, such holes must be filled with a material that prevents and/or retards the progress of a fire. Since the material that fills the hole prevents the migration of a fire through the slab, it is commonly called a “fire stop”.

A common approach to solving the problem of creating a fire stop is to fill the hole with mineral wool. For floor slabs, this creates the problem of the mineral wool disengaging from the hole and falling onto the floor below. Accordingly, this process is typically carried out by two persons, one on the upper floor and one on the floor below. The lower person prevents the disengagement of the mineral wool while the upper person is installing it into the hole. Once installed, plates are typically adhesively, or otherwise, secured over the upper and lower openings of the hole, thereby containing the mineral wool within the hole. It will be recognized that the lower plate could be secured first, followed by the same installer inconveniently having to move to the upper floor to subsequently install the mineral wool and the upper cover plate.

Various attempts have been made to overcome the aforementioned problem of stopping the migration of a fire from floor to floor (or though walls). One such previous device comprises a sandwich panel having a mineral wool core of appropriate thickness and highly thermally conductive sheets, wherein the sheets are tied together by filamentous strands as pre-manufactured. The sandwich panels may be cut and placed over openings in floors and/or walls. Unfortunately, because they require cutting, use of such panels is wasteful of material and, further, their placement over an opening cause a hazardous obstruction due to their required thickness. Similar panels comprise cover sheets held together by adhesives.

A similar device comprises an insulating core of mineral wool with a metal sheet adhesively secured to the insulating core cover. This typically requires cutting to a desired size prior to installation.

Still another device comprises mineral wool between panels that swell with heating. Again, the panels must be cut to size, resulting in waste, and must further be secured in an opening.

Yet another previous device comprises linings of intumescent material, such as fire putty, on opposite sides of a conduit with non-intumescent flame retardant material (with an optional sandwich core of mineral wool) cut to a dimension to fit an existing opening. In this device, the fire putty swells with heat to maintain the seal around the conduit. Again, this device must be cut to size with accompanying waste, and further does not provide a seal when the conduit is removed.

Therefore, it is readily apparent that there is a need for a fire stop in convenient form for installation by a single installer without the need for installation of separate components or dimensioning at a job site, and which further does not have a profile that causes it to be obstructively hazardous once installed.

BRIEF SUMMARY OF THE INVENTION

Briefly described, in a preferred embodiment, the present invention overcomes the above-mentioned disadvantages and meets the recognized need for such an apparatus by providing a fire stop and method of use thereof, wherein the fire stop comprises a device dimensioned to fit a selected size opening. The fire stop comprises end plates, a central member between the end plates that retains the end plates at a selected distance from one another, and a core between the end plates that comprises a first layer of fire putty and a second layer of mineral wool. The thickness and density of the mineral wool layer and/or the fire putty later can be chosen to achieve a particular fire rating within the constraints of the overall dimension not exceeding the thickness of the slab. The fire stop has a low profile rendering it non-obstructing, can be inserted by a single installer from above a floor slab or into a wall, and further can be removed for inspection and/or replacement as needed. Upon heating, the fire putty layer swells to fill any small remaining gaps between the fire stop and the diameter of the opening.

According to its major aspects and broadly stated, the present invention in its preferred form is a fire stop comprising a threaded shaft, a top plate, a dimensioning plate disposed proximate to and in contact with the top plate, and a bottom plate. The top plate and the bottom plate are secured on the shaft with fire putty and fire retardant wool, such as, for exemplary purposes only, mineral wool, disposed around the shaft between the top plate and the bottom plate. The top plate, the dimensioning plate and the bottom plate are secured on the threaded shaft via, for exemplary purposes only, nuts. The fire stop selectively comprises a printable sheath disposed over the fire putty and the fire retardant wool.

The fire putty is disposed proximate the dimensioning plate and the fire retardant wool is disposed proximate the bottom plate. It will be recognized that alternatively, the fire putty may be disposed proximate the bottom plate with the fire retardant wool disposed proximate the dimension plate. The fire retardant wool is selectively compressed between the bottom plate and the fire putty.

Additionally, a method of preventing fire migration between floors is provided comprising removing an existing through-slab conduit from a bore in a slab, selecting an appropriately-dimensioned fire stop, and inserting the fire stop into the bore in the slab.

More specifically, the present invention is a fire stop comprising a top plate, a bottom plate, a shaft, a dimensioning plate, a first nut, a second nut, fire retardant wool and fire putty. The fire retardant wool preferably comprises, for exemplary purposes only, mineral wool.

The shaft preferably comprises a flange and a barrel. The barrel is preferably threaded and is disposed within a throughhole in the top plate and an aperture in the dimensioning plate, passing through the top plate and the dimensioning plate. The flange is larger than the diameter of the throughhole, thereby retaining the shaft in communication with the top plate via engagement in contact with the top plate. The top plate and the dimensioning plate are secured in contact together on the shaft via a first nut. Tightening of the first nut on the shaft compresses the top plate and the dimensioning plate between the first nut and the flange.

The bottom plate is secured to the shaft via the second nut and contacts the fire retardant wool. The second nut and the bottom plate may selectively be utilized to compress the fire retardant wool. Alternatively, the bottom plate is secured to the shaft by an additional fastener, such as, for exemplary purposes only, another nut disposed between the second plate and the fire retardant wool.

It should be noted that, alternatively, the barrel of the shaft could be uniform in diameter, without threads, and the plates could be secured to the shaft by welding.

The fire putty surrounds the shaft and is in contact with the dimensioning plate. The fire retardant wool surrounds the shaft between the fire putty and the bottom plate, wherein the fire putty and the bottom plate retain the mineral wool in place.

The fire putty has first and second ends and the fire retardant wool has upper and lower ends. The first end of the fire putty contacts the dimensioning plate, and the second end is disposed proximate to the upper end of fire retardant wool, with the lower end of the fire retardant wool contacting the bottom plate.

The slab has a top surface and a bottom surface with bore extending through the slab from the top surface to the bottom surface. The fire stop is inserted into the bore, with its top plate above the top surface of the slab preventing the fire stop from passing completely through the bore. The fire stop extends substantially the full thickness of slab from the top surface to the bottom surface. The dimensioning plate is selected to have a diameter approximately the same as but slightly smaller than the diameter of the bore, thereby permitting the dimensioning plate to enter the bore, thereby retaining the fire stop in the opening and preventing the fire stop from movement parallel to the slab. By preventing such parallel movement, the fire stop is immobilized within the opening, thereby preventing slippage in the event that the fire stop is struck or otherwise contacted by persons and/or equipment being moved on the slab. The top plate is selected to be as thin as possible to provide a low profile that is less likely to be disturbed by persons inadvertently contacting the fire stop.

In use, during reconstruction and/or remodeling, plumbing and/or electrical conduits are typically removed from walls or slabs, leaving the bore open in the wall and/or slab. The bore opening could allow fire to spread from one surface of the wall or slab to the other. In order to prevent this, a fire stop of a selected appropriate diameter is inserted to block the bore. Upon insertion of the fire stop into the bore, fire is no longer able to pass through the wall or slab.

During a fire condition, heat causes the fire putty to swell, thereby causing the fire putty to expand and contact the wall of the bore providing an effective seal that retards and/or prevents passage of flame and/or hot gases through the bore.

In an alternate embodiment of the fire stop, a printable sheath covers the fire retardant wool and fire putty sections of the fire stop.

Accordingly, a feature and advantage of the present invention is its ability to stop penetration of a fire from one floor to another or through a wall.

Another feature and advantage of the present invention is its ability to be placed in position quickly without adjustment.

Still another feature and advantage of the present invention is its ability to be dimensioned to fit standard openings.

Yet another feature and advantage of the present invention is its ability to utilize different fire retardant materials.

Yet still another feature and advantage of the present invention is that it combines the benefits of different fire retardant materials.

These and other features and advantages of the present invention will become more apparent to one skilled in the art from the following description and claims when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present invention will be better understood by reading the Detailed Description of the Preferred and Selected Alternate Embodiments with reference to the accompanying drawing figures, in which like reference numerals denote similar structure and refer to like elements throughout, and in which:

FIG. 1 is a perspective view of fire stops according to a preferred embodiment, shown in the process of installation into a floor slab;

FIG. 2 is an exploded perspective view of a fire stop according to a preferred embodiment;

FIG. 3 is a perspective view of a fire stop according to an alternate embodiment; and

FIG. 4 is a side cross-sectional view of a fire stop according to a preferred embodiment, shown installed in a floor slab, subsequent to heat expansion of a fire putty component thereof.

DETAILED DESCRIPTION OF THE PREFERRED AND SELECTED ALTERNATE EMBODIMENTS OF THE INVENTION

In describing the preferred and selected alternate embodiments of the present invention, as illustrated in FIGS. 1-4, specific terminology is employed for the sake of clarity. The invention, however, is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish similar functions.

Referring now to FIGS. 1, 2 and 4, the present invention in a preferred embodiment is fire stop 10, wherein fire stop 10 comprises top plate 20, bottom plate 30, shaft 40, dimensioning plate 50, first nut 60, second nut 70, fire retardant wool 80 and fire putty 90, wherein fire retardant wool 80 preferably comprises, for exemplary purposes only, mineral wool. Shaft 40 is preferably threaded. It will be recognized by those skilled in the art that fire retardant materials other than fire putty 90 could be utilized, such as, for exemplary purposes only, fire caulk.

Referring now more specifically to FIGS. 1 and 2, shaft 40 preferably comprises flange 260 and barrel 270, wherein barrel 270 is preferably threaded, and wherein shaft 40 is preferably disposed within throughhole 150 of top plate 20 and aperture 160 of dimensioning plate 50, preferably passing through top plate 20 and dimensioning plate 50. Flange 260 is preferably larger than the diameter of throughhole 150, thereby preventing shaft 40 from passing fully through top plate 20, wherein flange 260 engages top plate 20. Top plate 20 and dimensioning plate 50 are preferably secured in contact together on shaft 40 via first nut 60, wherein tightening of first nut 60 on shaft 40 compresses top plate 20 and dimensioning plate 50 between first nut 60 and flange 260.

Bottom plate 30 is secured to shaft 40 in contact with fire retardant wool 80 via second nut 70, wherein second nut 70 and bottom plate 30 may selectively be utilized to compress fire retardant wool 80. Bottom plate 30 may alternatively be secured to shaft 40 by an additional fastener, such as, for exemplary purposes only, a nut disposed between bottom plate 30 and fire retardant wool 80.

Fire putty 90 is preferably disposed around shaft 40 in proximate contact with dimensioning plate 50 and fire retardant wool 80 is preferably disposed around shaft 40 between fire putty 90 and bottom plate 30, wherein fire putty 90 and bottom plate 30 retain fire retardant wool 80 in place on shaft 40. It will be recognized by those skilled in the art that alternatively fire putty 90 could be disposed proximate bottom plate 30 and fire retardant wool 80 could be disposed proximate to dimensioning plate 50, without departing from the spirit of the preferred embodiment.

Fire putty 90 preferably comprises first end 110 and second end 120 and fire retardant wool 80 preferably comprises upper end 130 and lower end 140, wherein first end 110 of fire putty 90 is preferably disposed proximate to and in contact with dimensioning plate 50, and wherein lower end 140 of fire retardant wool 80 is preferably disposed proximate to and in contact with bottom plate 30.

Second end 120 of fire putty 90 is preferably disposed proximate to upper end 130 of fire retardant wool 80, creating interface 100 between fire putty 90 and fire retardant wool 80.

Slab 190 comprises top surface 210, bottom surface 220 and bore 230 through slab 190 from top surface 210 and bottom surface 220, wherein fire stop 10 is preferably disposed in bore 230 of slab 190, and wherein top plate 20 is preferably disposed above top surface 210 of slab 190, and wherein fire stop 10 preferably extends substantially the full thickness of slab 190 from top surface 210 to bottom surface 220 thereof. Dimensioning plate 50 is preferably selected to have diameter 170 approximately the same as but slightly smaller than diameter 180 of bore 230, thereby permitting dimensioning plate to enter bore 230, retaining fire stop 10 in opening 200, wherein fire stop 10 is prevented from movement parallel to slab 190 and prevented from moving further through bore 230 by top plate 20.

Accordingly, by preventing such parallel movement, fire stop 10 is immobilized within opening 200 to prevent slippage in the event that fire stop 10 is struck or otherwise contacted by persons and/or equipment being moved on slab 190. It will be recognized by those skilled in the art that top plate 20 is preferably selected to be as thin as possible while still providing adequate rigidity to prevent fire stop 10 from passing completely through bore 230.

It will be recognized by those skilled in the art that plates 20, 30 and/or 50 could be secured to shaft 40 by means other than threaded retainers, such as nuts 60, 70, such as, for exemplary purposes only, via welding. It will be further recognized that, in such instance, shaft 40 could be non-threaded.

In use, during reconstruction and/or remodeling, plumbing and/or electrical conduits 240 are removed, leaving bore 230 open in slab 190. In such condition, fire could spread from bottom surface 220 to top surface 210. Accordingly, fire stop 10 of selected appropriate diameter is preferably inserted into slab 190 to block bore 230. Upon insertion of fire stop 10 into bore 230, bore 230 is no longer open and no longer permits fire to pass from bottom surface 220 to top surface 210 of slab 190. It will be recognized by those skilled in the art that alternatively, fire could originate at top surface 210 and be prevented by fire stop from passing through slab 190 to bottom surface 220. It will also be recognized by those skilled in the art that fire stop 10 could be utilized within wall surfaces in similar fashion to prevent fire from passing through same.

Turning now more particularly to FIG. 4, during a fire condition, heat causes fire putty 90 to swell, thereby causing fire putty 90 to contact wall 280 of bore 230 providing an effective seal that retards and/or prevents passage of flame and/or hot gases from passing through bore 230.

Referring now more specifically to FIG. 3, illustrated therein is an alternate embodiment of fire stop 10, wherein the alternate embodiment of FIG. 3 is substantially equivalent in form and function to that of the preferred embodiment detailed and illustrated in FIGS. 1, 2 and 4 except as hereinafter specifically referenced. Specifically, the embodiment of FIG. 3 comprises fire stop 10 having sheath 250 disposed over fire retardant wool 80 (best shown in FIG. 2) and fire putty 90 (best shown in FIG. 2). Sheath 250 comprises a material upon which printing of specifications and or source indicators may be disposed, wherein sheath 250 comprises a material that having fire retardant and/or ablative properties. It will be recognized by those skilled in the art that sheath 250 may be selectively very thin, wherein sheath 250 could be consumed by fire, instead of retarding same, without having effect on the properties of fire stop 10.

The foregoing description and drawings comprise illustrative embodiments of the present invention. Having thus described exemplary embodiments of the present invention, it should be noted by those skilled in the art that the within disclosures are exemplary only, and that various other alternatives, adaptations, and modifications may be made within the scope of the present invention. Merely listing or numbering the steps of a method in a certain order does not constitute any limitation on the order of the steps of that method. Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Although specific terms may be employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. Accordingly, the present invention is not limited to the specific embodiments illustrated herein, but is limited only by the following claims. 

1. A fire stop comprising: a shaft; a top plate; a bottom plate, wherein said top plate and said bottom plate are secured on said shaft; fire putty; and fire retardant wool, wherein said fire putty and said fire retardant wool are disposed around said shaft between said top plate and said bottom plate.
 2. The fire stop of claim 1, further comprising a dimensioning plate.
 3. The fire stop of claim 2, wherein said dimensioning plate is disposed proximate to and in contact with said top plate.
 4. The fire stop of claim 2, wherein said shaft is threaded.
 5. The fire stop of claim 4, wherein said top plate, said dimensioning plate and said bottom plate are secured on said threaded shaft via nuts.
 6. The fire stop of claim 3, wherein said fire putty is disposed proximate to said dimensioning plate.
 7. The fire stop of claim 6, wherein said fire retardant wool is disposed proximate said bottom plate.
 8. The fire stop of claim 7, wherein said fire retardant wool is compressed between said bottom plate and said fire putty.
 9. The fire stop of claim 3, wherein said fire putty is disposed proximate to said bottom plate.
 10. The fire stop of claim 9, wherein said fire retardant wool is disposed proximate said dimensioning plate.
 11. The fire stop of claim 1, wherein said fire retardant wool comprises mineral wool.
 12. The fire stop of claim 1, further comprising a printable sheath disposed over said fire putty and said fire retardant wool.
 13. A method of preventing fire migration between floors, said method comprising the steps of: removing an existing through-slab conduit from a bore in a slab; selecting an appropriately-dimensioned fire stop, wherein said fire stop comprises a top plate, a bottom plate, a shaft between said top plate and said bottom plate, said shaft having fire putty and fire retardant wool disposed therearound between said top plate and said bottom plate; and inserting said fire stop into the bore in the slab.
 14. The method of claim 13, further comprising the step of: compressing said fire retardant wool.
 15. A fire stop comprising: a shaft; a top plate; a dimensioning plate: a bottom plate, wherein said top plate, said dimensioning plate and said bottom plate are secured on said shaft; fire putty; and mineral wool, wherein said fire putty and said mineral wool are disposed around said shaft between said dimensioning plate and said bottom plate.
 16. The fire stop of claim 15, further comprising a printable sheath around said fire putty and said flame retardant wool. 